Abstract Thu004: S timulation-Conduction Platform Enhances Induced Pluripotent Stem Cell-Derived Cardiomyocyte Electrophysiology

Introduction: Induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) theoretically offer infinite autologous cells for cardiac tissue engineering, but in reality are immature and thus unsuitable for use. Electrical stimulation and, to a lesser extent, conductive scaffolds, have been shown to promote electrophysiological function in cardiac cultures. We hypothesize that synergistic application of electrical stimulation and conductive scaffolds to iPSC-CMs will electrophysiologically mature them. Approach: We designed a novel bioreactor (Fig. 1A-C) consisting of a custom plate cover with carbon electrodes and modular elements controlled by a printed circuit board. We used our bioreactor to apply electrical stimulation (0.1, 1, and 10 V; 5 ms period; 20% duty cycle) to iPSC-CMs on conductive carbon nanotube (CNT) scaffolds and used RT-qPCR to analyze their response. Results: Electrical stimulation of iPSC-CMs resulted in primarily upregulation of electrophysiology-related genes when compared to non-stimulated iPSC-CMs (Fig. 1D). Additionally, stimulation with 0.1 and 1 V resulted in earlier automaticity as observed by spontaneous beating. Furthermore, electrical stimulation of iPSC-CMs seeded on CNT scaffolds (with and without laminin coating) revealed that direct contact with CNT scaffolds predominantly upregulated cardiac genes (Fig. 1E), whereas iPSC-CMs whose direct contact with CNT scaffolds was interrupted by laminin coating experienced predominantly downregulation of cardiac genes (Fig. 1F). This suggests that CNT scaffolds provide a superior microenvironment than commonly-used laminin for the development of iPSC-CM structure and function. Conclusions: Our combined stimulation-conduction platform constitutes a novel method for developing iPSC-CM electrophysiology, which has the potential to play a role in making iPSC-CMs more relevant for both diagnostic and therapeutic applications.